Decoherence and pointer states in small antiferromagnets: A benchmark test

Submission summary

 As Contributors: Hylke Donker Arxiv Link: http://arxiv.org/abs/1612.03099v3 Date accepted: 2017-02-24 Date submitted: 2017-02-17 Submitted by: Donker, Hylke Submitted to: SciPost Physics Domain(s): Computational Subject area: Quantum Physics

Abstract

We study the decoherence process of a four spin-1/2 antiferromagnet that is coupled to an environment of spin-1/2 particles. The preferred basis of the antiferromagnet is discussed in two limiting cases and we identify two $\it{exact}$ pointer states. Decoherence near the two limits is examined whereby entropy is used to quantify the $\it{robustness}$ of states against environmental coupling. We find that close to the quantum measurement limit, the self-Hamiltonian of the system of interest can become dynamically relevant on macroscopic timescales. We illustrate this point by explicitly constructing a state that is more robust than (generic) states diagonal in the system-environment interaction Hamiltonian.

List of changes

1) The figures have been enlarged, in particular Figs. 2 & 5.

2) The units of time t is stressed in the captions of the figures.

Submission & Refereeing History

Resubmission 1612.03099v3 (17 February 2017)
Resubmission 1612.03099v2 (31 January 2017)
Submission 1612.03099v1 (12 December 2016)